(fus'tē), —adj., -ti•er, -ti•est.1. having a stale smell; moldy; musty: fusty rooms that were in need of a good airing.2. old-fashioned or out-of-date, as architecture, furnishings, or the like: They still live in that fusty, gingerbread house. 3. stubbornly conservative or old-fashioned; fogyish.